1. The Field of the Invention
The present invention relates generally to medical devices and methods. More specifically, the present invention relates generally to introducer sheaths having a valve.
2. The Relevant Technology
A wide variety of introducer sheaths have been developed for medical use. Introducer sheaths are often used to access a vessel or artery to allow a surgical procedure to be performed. For example, introducer sheaths are often used for medical procedures that utilize catheters, such as angioplasty or stenting procedures. In practice, the introducer sheath is typically inserted into the patient's vasculature using the modified Seldinger technique. Under the Seldinger technique, a needle is first inserted into the vessel. A guidewire is then inserted through the needle and into the vessel. Next, the needle is removed and a sheath/dilator combination is advanced over the guidewire. The dilator is used to expand the puncture in the vessel to a size suitable to receive an introducer sheath. After the distal end of the sheath is disposed within the vessel, the dilator and guidewire are removed, thereby allowing access to the vessel.
Conventionally, introducer sheaths are formed of three or more components that require assembly: an elongated tubular member, a hub portion, and a hemostasis valve disposed within the hub portion. In some designs an introducer sheath may also include a strain relief member which is disposed adjacent the distal end of the hub and about the proximal end of the elongated tubular portion. A suitable example of such an assembly is shown in U.S. Pat. No. 5,807,350, which discloses an introducer sheath having a construction similar to that described above, the entirety of which is hereby incorporated herein by reference.
Introducer sheaths, such as that described above, are generally constructed of multiple pieces which must be assembled to form the sheath. In most cases, the distal end of the hub portion is molded over the elongated tubular member. While molding may produce a stronger part, there is the possibility of damaging a portion of the other components of the device during the process. Any such damage results in the entire device having to be thrown away. As a result, there is a need for a way to attach the proximal end of the tubular member to the distal end of the hub portion which still meets all of the requirements of the introducer sheath, including but not limited to forming a fluid seal and having sufficient strength between the attachment of the hub portion and the tubular member to remain attached, but does not require throwing the entire device away if a portion of the sheath is damaged during manufacturing or assembly. Thus, there is a need for a new introducer sheath having lower manufacturing costs and higher quality control while still retaining the important requirements for an introducer sheath.